Carrier for developing electrostatic latent image, two-component developer, developer for replenishment, image forming device, process cartridge, and image forming method

Abstract

A carrier for developing an electrostatic latent image includes a core material particle and a resin layer covering a surface of the core material particle. The resin layer includes a resin and at least one kind of a fine particle. At least one kind of the fine particles includes a chargeable fine particle. The chargeable fine particle has a long diameter of 400 to 900 nm. The chargeable fine particle has a shape factor SF-1 of 160 to 250.

The invention claimed is: 
     
       1. A carrier for developing an electrostatic latent image, the carrier comprising:
 a core material particle and a resin layer covering a surface of the core material particle, wherein 
 the resin layer includes a resin and at least one kind of a fine particle; 
 the at least one kind of the fine particles includes a conductive fine particle and a chargeable fine particle; 
 the chargeable fine particle has a long diameter of 400 to 900 nm; and 
 the chargeable fine particle has a shape factor SF-1 of 160 to 250. 
 
     
     
       2. The carrier for developing an electrostatic latent image according to  claim 1 , wherein the resin layer has a thickness of 0.2 to 2.0 μm. 
     
     
       3. A two-component developer comprising:
 the carrier for developing an electrostatic latent image according to  claim 1 ; and 
 a toner. 
 
     
     
       4. The two-component developer according to  claim 3 , wherein the toner is a color toner. 
     
     
       5. An image forming device comprising:
 an electrostatic latent image bearer; 
 a charging unit configured to charge the latent image bearer; 
 an exposure unit configured to form an electrostatic latent image on the latent image bearer; 
 a developing unit configured to develop the electrostatic latent image formed on the electrostatic latent image bearer using the two-component developer according to  claim 3  to form a toner image; 
 a transfer unit configured to transfer the toner image formed on the electrostatic latent image bearer to a recording medium; and 
 a fixing unit configured to fix the toner image transferred to the recording medium. 
 
     
     
       6. A process cartridge comprising:
 an electrostatic latent image bearer; 
 a charging unit configured to charge a surface of the electrostatic latent image bearer; 
 a developing unit configured to develop an electrostatic latent image formed on the electrostatic latent image bearer using the two-component developer according to  claim 3 ; and 
 a cleaning unit configured to clean the electrostatic latent image bearer. 
 
     
     
       7. An image forming method comprising:
 forming an electrostatic latent image on an electrostatic latent image bearer; 
 developing the electrostatic latent image formed on the electrostatic latent image bearer with the two-component developer according to  claim 3  to form a toner image; 
 transferring the toner image formed on the electrostatic latent image bearer to a recording medium; and 
 fixing the toner image transferred to the recording medium. 
 
     
     
       8. The carrier of  claim 3 , wherein the chargeable fine particle exhibits reverse chargeability with respect to the toner and imparts negative chargeability to the toner through friction with the toner. 
     
     
       9. A developer for replenishment comprising a carrier and a toner, wherein
 the developer includes 2 to 50 parts by mass of the toner relative to 1 part by mass of the carrier, and 
 the carrier is the carrier for developing an electrostatic latent image according to  claim 1 .